A tote bin is a bin or storage system which holds or carries bulk product. Tote bins are generally filled with a bulk product for the purposes of storing and transporting that bulk product to an end user.
Typically, such tote bins are lined with a plastic or polymer liner which holds the bulk product. The liner has an outlet tube or spigot hermetically sealed by a membrane. The outlet spigot allows for connection to a valve so as to fill or empty the product from the liner. The valve may or may not be attached during transport.
The products which are stored and carried in tote bins typically require sanitary or sterile conditions for the filling and emptying procedures. In the case of food product sterile conditions are generally required.
To achieve a required degree of sterility all surfaces which will contact the product need to be sterilised. Thus when filling or emptying the tote bin the valve is attached in a manner so that both the valve and the membrane can be sterilised together.
One of the disadvantages of prior art tote bins which have plastic liners is that the membrane which seals the outlet spigot is arranged on the outlet spigot in such a way that it is not readily sterilisable without a risk that the membrane or its seal to the spigot will be damaged by the fluid used for sterilisation.
A typical arrangement of a prior art outlet spigot and valve is illustrated in FIGS. 1 and 2. In FIGS. 1 and 2 the outlet spigot is generally indicated by the letter “A” and is illustrated as being attached to a liner indicated with the letter “L”. The outlet spigot A has a membrane E hermetically sealed thereto.
A butterfly valve “B” is connected to the outlet spigot A as depicted in FIG. 2. The valve B includes a ring shaped cylindrical cutter C having a cut out segment. The cutter C is slidably located in the valve passage D, between a butterfly valve member G and the membrane E. The cutter C is a cylindrical ring with a cut out segment. When the valve B is closed the cutter C will not engage the membrane E until the valve is opened.
Once the valve B has been connected to the outlet A, and upon opening the butterfly valve member G, as illustrated in FIG. 2, the cutter C is moved to the left of the figure by an edge H of the valve member B. The edge H engages a bar J on the cutter C. The cutter C will then engage and cut the membrane E.
As the cutter C is a cylindrical ring with a cut out segment, it leaves a portion of the membrane uncut, thereby leaving a land which connects the cut portion of the membrane with the uncut. The land forms a hinge arrangement.
The arrangement illustrated in FIGS. 1 and 2 leads to several difficulties during sterilising procedures.
The first is that as soon as the valve B is opened, the membrane E is pierced by the cutter C. This means that for the arrangement of FIGS. 1 and 2 the valve components, seals and membrane cannot be sterilised through the valve.
To overcome this difficulty an additional inlet can be provided to allow the entry of a sterilising medium into the valve between the membrane E and the butterfly valve member G. In this case, prior to the opening of the butterfly valve member G, a sterilising medium is injected into the region between the butterfly valve member G and the membrane E to sterilise the membrane E, the internal portions of the outlet spigot A, the cutter C and some of the internal portions of the valve B. In this situation there will still remain the difficulty mentioned previously that the membrane or the seal between it and the outlet spigot will have the potential to be damaged.
The potential to be damaged dictates the maximum temperature and pressure at which sterilisation occurs. This in turn generally means a lower temperature and pressure sterilisation procedure will have to be used which in turn dictates that a long time will be used to achieve the necessary level of sterilisation.
One of the disadvantages of sterilising at a temperature and or pressure which is not as high as it should optionally be, is that it can take so long to complete the sterilisation process that downstream processes can be delayed.
It is an object of the present invention to provide a combination of a valve and spigot for attachment to a lined tote bin, and/or a method of sterilising and filling or emptying a lined tote bin and/or a cutter for a membrane which ameliorates, at least in part, at least one of the prior disadvantages of the prior art.